I have downloaded the Stackoverflow data dump updated as of August 2012 [0]. I am particularly interested in the history of a particular post and therefore, I want to concentrate on posts.xml and posthistory.xml files. The details of the XML file according to readme.txt is as follows :

- **posts**.xml
- Id
- PostTypeId
- 1: Question
- 2: Answer
- ParentID (only present if PostTypeId is 2)
- AcceptedAnswerId (only present if PostTypeId is 1)
- CreationDate
- Score
- ViewCount
- Body
- OwnerUserId
- LastEditorUserId
- LastEditorDisplayName="Jeff Atwood"
- LastEditDate="2009-03-05T22:28:34.823"
- LastActivityDate="2009-03-11T12:51:01.480"
- CommunityOwnedDate="2009-03-11T12:51:01.480"
- ClosedDate="2009-03-11T12:51:01.480"
- Title=
- Tags=
- AnswerCount
- CommentCount
- FavoriteCount
- **posthistory**.xml
- Id
- PostHistoryTypeId
- 1: Initial Title - The first title a question is asked with.
- 2: Initial Body - The first raw body text a post is submitted with.
- 3: Initial Tags - The first tags a question is asked with.
- 4: Edit Title - A question's title has been changed.
- 5: Edit Body - A post's body has been changed, the raw text is stored here as markdown.
- 6: Edit Tags - A question's tags have been changed.
- 7: Rollback Title - A question's title has reverted to a previous version.
- 8: Rollback Body - A post's body has reverted to a previous version - the raw text is stored here.
- 9: Rollback Tags - A question's tags have reverted to a previous version.
- 10: Post Closed - A post was voted to be closed.
- 11: Post Reopened - A post was voted to be reopened.
- 12: Post Deleted - A post was voted to be removed.
- 13: Post Undeleted - A post was voted to be restored.
- 14: Post Locked - A post was locked by a moderator.
- 15: Post Unlocked - A post was unlocked by a moderator.
- 16: Community Owned - A post has become community owned.
- 17: Post Migrated - A post was migrated.
- 18: Question Merged - A question has had another, deleted question merged into itself.
- 19: Question Protected - A question was protected by a moderator
- 20: Question Unprotected - A question was unprotected by a moderator
- 21: Post Disassociated - An admin removes the OwnerUserId from a post.
- 22: Question Unmerged - A previously merged question has had its answers and votes restored.
- PostId
- RevisionGUID: At times more than one type of history record can be recorded by a single action. All of these will be grouped using the same RevisionGUID
- CreationDate: "2009-03-05T22:28:34.823"
- UserId
- UserDisplayName: populated if a user has been removed and no longer referenced by user Id
- Comment: This field will contain the comment made by the user who edited a post
- Text: A raw version of the new value for a given revision
- If PostHistoryTypeId = 10, 11, 12, 13, 14, or 15 this column will contain a JSON encoded string with all users who have voted for the PostHistoryTypeId
- If PostHistoryTypeId = 17 this column will contain migration details of either "from <url>" or "to <url>"
- CloseReasonId
- 1: Exact Duplicate - This question covers exactly the same ground as earlier questions on this topic; its answers may be merged with another identical question.
- 2: off-topic
- 3: subjective
- 4: not a real question
- 7: too localized

Now, how can I know the PostHistoryTypeId of a particular post. I would imagine that the posts.xml file would have a PostId field but apparently it doesn't. Am I missing something here or this intentional?